Figure 1

Flowchart of constructing the network marker at 3 time points post-stroke. We integrated microarray data, a gene ontology database, and protein-protein interaction (PPI) information to construct PPI networks (PPINs). These data were used for the differential protein pool selection, and then the selected proteins and their corresponding microarray data were used for the contribution of PPIN by a maximum-likelihood estimation and model order detection methods, resulting in a stroke PPIN (SPPIN) and a normal PPIN (NPPIN) in the 3 stages (3, 5, and 24 h post-stroke) of stroke. The 2 constructed PPINs were used to determine critical proteins of stroke by the difference of SPPIN and NPPIN matrices. By the help of the differential value of these two networks, the stroke relevance value (SRV) was computed for each protein, and significant proteins in the stroke recovery process were determined based on p values of the SRVs. These significant critical proteins with top SRVs were obtained as network markers for the 3 stages of stroke.